Preya Shabrina

Developers rely on open-source packages and must review dependencies to safeguard against vulnerable or malicious upstream code. A careful review of all dependencies changes often does not occur in practice. Therefore, developers need signals to inform of dependency changes that require additional examination, particularly measures for contributor reputation. The goal of this study is to help developers prioritize dependency review efforts by analyzing contributor reputation measures as a signal in the Rust ecosystem. We use network centrality measures to proxy contributor reputation using collaboration activity. We employ a mixed method methodology from the top 1,644 packages in the Rust ecosystem to build a network of 6,949 developers, survey 285 developers, and model 5 centrality measures. Through our survey, we find that only 24% of respondents often review dependencies before adding or updating a package, mentioning difficulties in the review process and signals are therefore employed. Particularly, 51% of respondents often consider contributor reputation when reviewing dependencies. We further explore contributor reputation through network centrality measures employing multivariate mixed-effect linear regression models. We find that the closeness centrality measure is a significant factor in explaining how developers choose to review dependencies. Yet, centrality measures alone do not account for how developers choose to review dependencies. We recommend the Rust ecosystem implement a contributor reputation badge based on our modeled coefficients to complement developers’ dependency review efforts.

Data-driven programming feedback systems can help novices to program in the absence of a human tutor. Prior evaluations showed that these systems improve learning in terms of test scores, or task completion efficiency. However, crucial aspects which can impact learning or reveal insights important for future improvement of such systems are ignored in these evaluations. These aspects include inherent fallibility of current state-of-the-art, students' programming behavior in response to correct/incorrect feedback, and effective/ineffective system components. Consequently, a great deal of knowledge is yet to be discovered about such systems. In this paper, we apply a multi-criteria evaluation with 5 criteria on a data-driven feedback system integrated within a block-based novice programming environment. Each criterion in the evaluation reveals a unique pivotal aspect of the system: 1) How accurate the feedback system is; 2) How it guides students throughout programming tasks; 3) How it helps students in task completion; 4) What happens when it goes wrong; and 5) How students respond generally to the system. Our evaluation results showed that the system was helpful to students due to its effective design and feedback representation despite being fallible. However, novices can be negatively impacted by this fallibility due to high reliance and lack of self-evaluation. The negative impacts include increased working time, implementation, or submission of incorrect/partially correct solutions. The evaluation results reinforced the necessity of multi-criteria system evaluations while revealing important insights helpful to ensuring proper usage of data-driven feedback systems, designing fallibility mitigation steps, and driving research for future improvement.

Learning to derive subgoals reduces the gap between experts and students and makes students prepared for future problem solving. Researchers have explored subgoal labeled instructional materials with explanations in traditional problem solving and within tutoring systems to help novices learn to subgoal. However, only a little research is found on problem-solving strategies in relationship with subgoal learning. Also, these strategies are under-explored within computer-based tutors and learning environments. Backward problem-solving strategy is closely related to the process of subgoaling, where problem solving iteratively refines the goal into a new subgoal to reduce difficulty. In this paper, we explore a training strategy for backward strategy learning within an intelligent logic tutor that teaches logic proof construction. The training session involved backward worked examples (BWE) and problem-solving (BPS) to help students learn backward strategy towards improving their subgoaling and problem-solving skills. To evaluate the training strategy, we analyzed students' 1) experience with and engagement in learning backward strategy, 2) performance, and 3) proof construction approaches in new problems that they solved independently without tutor help after each level of training and in post-test. Our results showed that, when new problems were given to solve without any tutor help, students who were trained with both BWE and BPS outperformed students who received none of the treatment or only BWE during training. Additionally, students trained with both BWE and BPS derived subgoals during proof construction with significantly higher efficiency than the other two groups.